announcements next exam is scheduled for monday march 31. due to the ice week, it will be delayed...
TRANSCRIPT
![Page 1: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/1.jpg)
Announcements• Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the rest of Chapter 5 (from Kepler) and all of Chapter 6 and some of Chapter 7. Sample questions will be posted tomorrow.
• Dark Sky Observing Night tonight! Forecast looks good: clear but cold. Set-up starts at 7:30pm.
![Page 2: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/2.jpg)
The problem of Longitude
Finding your latitude is easy, just measure the altitude of Polaris to get close. To be precise you need to know how far Polaris is from the NCP
![Page 3: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/3.jpg)
Measuring longitude requires
determining your angle
from a reference
line on Earth
![Page 4: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/4.jpg)
The Longitude Act of 1714 offered a £20,000 prize for an
accurate method of determining longitude at sea
The matter was brought to a head after a particularly disastrous shipwreck in 1707 in which four large ships and over 1400 sailors of the Royal Navy perished
![Page 5: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/5.jpg)
Early methods involved measuring the moons of Jupiter
Once their orbits were determined, ephemeredes could be generated to show their location at any time in the future. Then all you have to do is accurately measure your local time.
![Page 6: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/6.jpg)
Accurate ephemeredes of Jupiter’s moons became available in 1668
Gian Domenico Cassini
![Page 7: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/7.jpg)
The problem was it isn’t possible to accurately
measure the moons of
Jupiter from the deck of a rolling ship
![Page 8: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/8.jpg)
If you could accurately measure the difference between true north and magnetic north, that might work
Problem was the magnetic pole isn’t stable, it moves over time
![Page 9: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/9.jpg)
Next came attempts to use the Moon to measure time
An eclipse is seen by everyone on Earth at the same time
![Page 10: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/10.jpg)
The location of the Moon with respect to the background stars
could be used if…
![Page 11: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/11.jpg)
Nevil Maskelyne, Astronomer Royal, published his first Nautical
Almanac in 1766
![Page 12: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/12.jpg)
Again, the problem is
making astronomical observations from the deck
of a rolling ship at sea
![Page 13: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/13.jpg)
John Harrison
came up with the solution:
make an accurate and stable clock
![Page 14: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/14.jpg)
Harrisons 1st attempt
in 1735 used a double
pendulum design
![Page 15: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/15.jpg)
He continues with several other models
H3 front and back H4 tested in 1764
H4 passes several sea trials and meets all the requirements but isn’t awarded the prize due to “land trials” at Greenwich
![Page 16: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/16.jpg)
His final model, H5 built in 1770, has better than the required accuracy
![Page 17: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/17.jpg)
James Cook took one of the copies on a voyage to the Pacific
![Page 18: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/18.jpg)
It took many years and a
Royal Decree before
Harrison was finally awarded £8,750 by act of Parliament
in 1773
![Page 19: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/19.jpg)
Chaos in the Solar System
At its very inception, Newton knew that it would be impossible to get a “closed solution” to the three body problem
![Page 20: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/20.jpg)
The orbits of all the planets are known to have long-term variations
![Page 21: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/21.jpg)
The biggest problems were with the orbits of Jupiter and Saturn
Their interactions led to periodic variations and what appeared to be non-periodic changes
![Page 22: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/22.jpg)
Lagrange and Laplace showed the seemingly non-periodic variations
were, in fact, periodic
Lagrange Laplace
![Page 23: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/23.jpg)
Laplace eventually forms a theory for why the solar system is as it is
![Page 24: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/24.jpg)
Laplace’s Traite de
mecanique celeste
becomes the
standard of celestial
mechanics
![Page 25: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/25.jpg)
The “missing planets” problem
The Titus-Bode Law predicted a planet between Mars and Jupiter. At the time, Uranus
and Neptune had not been discovered
0.4 0.3 2 ,0,1,2,3,4,...ma where m
![Page 26: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/26.jpg)
On March 13, 1781 William Herschel discovered Uranus
Its’ orbit matched the
Titus-Bode Law
![Page 27: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/27.jpg)
Baron Franz Xaver von Zach
quickly forms the “Celestial
Police” to hunt down the
missing planet between Mars
and Jupiter
![Page 28: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/28.jpg)
Purely by chance, Giuseppi Piazzi discovers
the “missing planet” on
January 1, 1801. He names it
Ceres
![Page 29: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/29.jpg)
Ceres is “lost” for a while but Carl Friedrich Gauss, at the
Berlin Observatory, calculates an orbit and re-
finds it
![Page 30: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/30.jpg)
Within a year Heinrich Olbers discovers another body he names
Pallas
![Page 31: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/31.jpg)
By 1807, two more objects, Juno and Vesta are discovered
![Page 32: Announcements Next exam is scheduled for Monday March 31. Due to the ice week, it will be delayed one week to Monday April 7. Tentatively will cover the](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649ef55503460f94c08315/html5/thumbnails/32.jpg)
Olbers thought all the asteroids originated from
a single “exploded” planet but
orbital calculations
proved otherwise By 1850 over a dozen objects
had been discovered